(a) Field of the Invention
The present invention relates to a backlight assembly, a display device and a driving apparatus of a light source for the display device.
(b) Description of Related Art
Display devices used for monitors of computers and television sets generally include either self-emitting display devices such as organic light emitting displays (OLEDs), vacuum fluorescent displays (VFDs), field emission displays (FEDs), and plasma panel displays (PDPs), or non-emitting display devices such as liquid crystal display (LCD) devices requiring an external light source.
An LCD device includes two panels provided with field-generating electrodes and a liquid crystal (LC) layer having dielectric anisotropy disposed between the two panels. The field-generating electrodes are supplied with voltages to generate an electric field across the LC layer, and a light transmittance of the LC layer varies in response to a strength of the electric field, which is controlled by the voltages supplied. Accordingly, desired images are displayed by adjusting the voltages supplied. The external light source for the LCD devices may be an artificial light source that is installed in the LCD devices or natural light.
The artificial light source, which is part of a backlight assembly, is often implemented with a plurality of fluorescent lamps that are connected to a plurality of inverters for driving each of the lamps. Each of the inverters receives a DC (direct current) input voltage from an external source and converts it to an AC (alternating current) voltage, which is applied to each of the lamps to turn on each of the lamps and to control brightness of each of the lamps. The AC voltage may be stepped up by a transformer prior to being applied to each of the lamps. The inverter also senses a monitored voltage related to a current flowing through each of the lamps and controls the AC voltage applied to each of the lamps based on the monitored voltage.
The lamps may be disposed under an LC panel assembly, such as in a direct-type backlight assembly, or may be disposed along one or more edges of the LC panel assembly, such as in an edge-type backlight assembly.
As explained above, the conventional artificial light sources require several peripheral devices such as inverters and sensors, which undesirably increase manufacturing cost.